Page 37 - Handbook of Adhesion Promoters
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30 Mechanisms of Adhesion
Figure 2.32. PVA mortar/hydrophilic active surface interaction model. [Adapted, by permission, from
Mansur, AAP; Mansur, HS, Cement Concrete Compos., 33, 742-8, 2011.]
The hydrophilic silane functionalities and mercaptan and amine groups improved
56
interfacial strength between tiles and the modified mortar. The adhesion mechanism is
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schematically shown in Figure 2.32. In addition to the hydrophilic interactions (NH and
2
SH groups with OH groups of glass tiles), the development of covalent bonds between
alkoxy-derived (Si−OH) from silane and hydroxyl groups from PVA (alcohol units)
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should be taken into consideration. The interfacial strength was increased by 36% with
56
mercapto-silane and by 20% with amino-silane.
The mechanism of silane deposition onto aluminum surface, in the presence of
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organophosphonic acid as adhesion promoter, was studied. Transparent thin films of lay-
ered inorganic-organic composites were prepared by the sol-gel synthesis of tetraethy-
